Fluid power system and valve mechanism therefor



Feb. 21, 1967 A. NEVULIS 3,304,841

FLUID POWER SYSTEM AND VALVE MECHANISM THEREFOR Filed Jan. 2, 1964 INVENTOR.

ANTHONY NEVULIS BY 7M Whiz Ml? ATTORNEYS United States Patent 3,304,841 FLUID POWER SYSTEM AND VALVE MECHANISM THEREFOR Anthony Nevulis, Wicklitfe, Ohio, assignor to The Ohio Brass Company, Mansfield, Ohio, a corporation of New Jerse y Filed Jan. 2, 1964, Ser. No. 335,175

14 Claims. (Cl. 91-436) This invention relates in general to fluid power systems, and more particularly to a valve mechanism, for use in a fluid powered system for providing a regenerative c1rcuit therefor.

This system is adapted for use, for instance, in loading or excavating mechanism, wherein a fluid powered reciprocal type motor unit or units actuate a scoop or bucket, for digging or shifting material. With the regenerative circuit arrangement of the instant invention, fluid or oil being forced from one side of the motor unit during actuation of the latter can be returned to the other side of the motor unit, for aiding in actuating the piston of the motor unit, so that the pump of the system need only supply an amount of pressurized fluid sufficient to compensate for the volume displacement of the piston rod.

Accordingly, an object of the invention is to provide a novel fluid power system for operating mechanism and one which incorporates a regenerative feature therein.

Another object of the invention is to provide a novel control valve for a fluid powered system which is effective to control the application of pressurized fluid from one side of a fluid powered motor unit for permitting flow of the fluid back to reservoir from the opposite side of the motor unit, but which upon actuation of the motor unit in the opposite direction, causes the fluid in said one side of the motor unit to be applied to the opposite side thereof, for aiding in actuating the motor unit.

Other objects and advantages of the invention will be apparent from the following description taken in conjunction with the accompanying drawings wherein:

FIG. 1 is a generally diagrammatic, partially sectioned view of a system embodying the instant invention, and one that may be eflectively used for operating a bucket or scoop of an excavating machine.

FIG. 2 is a fragmentary, diagrammatic view of a possible arrangement of the control valve of the system on a boom of a scoop loading or excavating machine, for controlling associated reciprocal type motor units which are adapted to actuate the scoop of the machine.

Referring now again to the drawings, there is shown a regenerative valve or control valve member 10, which may be mounted adjacent the outer end of a preferably vertically swingable boom 12, which may represent the boom of a loading or excavating tractor or machine, with the boom pivotally mounting a bucket or scoop 14 thereon, and with reciprocal, fluid powered, double acting motor unit or units 16, 16a operating between the boom 12 and the bucket 14, for actuating the latter about its pivot point 18. As can be seen, the reciprocal motor unit 16 may be pivotally coupled as at 17 to the boom and can be coupled as at 17a to the bucket 14.

The valve member 10, with which the present invention is especially concerned, may be mounted in close proximity to the reciprocal motor unit 16, and as for instance on the boom frame 12, with the valve member 10 being adapted to receive pressurized actuating fluid, such as for instance pressurized oil, from a conventional distributing valve member 20 (FIG. 1) which in turn may receive pressurized fluid from a pump 18 and reservoir 18a, as utilized in conventional fluid power systems.

The distributing valve 20 may be of the manually operated type, including a control handle 20a operatively .coupled to an axially movable spool 20b, and which upon axial movement of the spool in the conventional manner determines which of the valve ports 22, 22a of the distributing valve is pressurized, one of the ports 22, 22a being coupled to the source of pressurized fluid while the other port is coupled back to reservoir. Valve 20 may be of the conventional open center type of distributing valve.

Valve 10 may comprise a body portion 26 having ports 28, 28a and 28b therein. Associated with ports 28, 28a is a valve mechanism 30, comprising a cylindrical tubular member 32 slidable in a vertical (in the embodiment illustrated) passageway in the valve 10, defined in part by a chamber 34 and a chamber 36, with an opening 37 in Web 37a communicating chambers 34 and 36. Opening 37 slidably receives the tubular member 32 for axial movement thereof, with such tubular member being normally urged into abutting engagement with abutment surface 39 provided by threaded cap member 40, and by means of spring 42 coacting between seat 44 on the slidable valve member 32 and a seat 46 in cap member 48. The seat 44 is provided with an orifice 50 therethrough, communicating the interior of cap member 48 with the interior of valve member 32. Valve member 32 has a plurality of circumferentially spaced orifices 52 normally communicating the interior of member 32 with chamber 34, and a plurality of relatively larger size circumferentially spaced orifices 54 spaced vertically or axially from orifices 52 and communicating the interior of member 32 with the aforementioned chamber 36 in the valve body 26.

Positioned in member 32 intermediate the orifice groups 52 and 54 is a plate 56 having an orifice 58 which is of preferably circular configuration, and which is disposed in mounted relation on lip 58a of member 3 2, and which is held in position by a snap ring 60 received in a complementary recess in the defining wall of member 32. Orifice 58 preferably has convergent entry surface 62 merging into opening 58 through the orifice plate 56 and communicating the uppersection 64 of member 32 with the lower section 64a thereof.

Associated with port 28b of control valve body 26 is a check valve mechanism 66 disposed in a passageway in the valve body 26. Such passageway is defined in part by a chamber 68, a chamber 70 and a chamber 72, such chambers 68, 70 and 72 being connected by openings 78 and 78a, communicating such chambers with one another.

Cap member 80 extends into chamber 68 and opening 78, and is provided with sealing means 80a which seals the exterior or skirt of the cap member 80 to the interior of opening 78.

Cap member 80 defines a cylinder chamber 82 in which is disposed a piston member 84 of valve mechanism 66. A spring 84a coacts between the cap member 80 and the piston member 84, to oppose upward movement (with reference to FIG. 1) of the piston member 84 toward the cap member. Sealing means 85 coacts between the defining wall of the cylindrical chamber 82 and the piston member 84. A tubular seat member 86 may be pres fitted or otherwise secured in opening 78a and chamber 72, with a poppet-like valve member 87 coacting with the seat member 86 and ordinarily sealing chamber 70 from chamber 72. A spring member 88 coacting between the piston member 84 and the poppet member 87 urges the poppet valve 87 into sealing engagement with the seat.

As can be seen, the poppet valve 87 is mounted upon and supported by stem section 89 of the piston 84, and with sealing means 89a coacting between the poppet valve 87 and the stem section 89, for sealing therebetween. Also the piston member has a shoulder portion 90 thereon which is adapted for engagement with the valve member 87, to limit movement of the valve member 87 in a direction toward the spring 88. Seat member 86 has openings 94 extending therethrough communicating the interior of the seat member 86 with chamber 72.

The distal end of stem section 89 of the piston member 84 preferably includes a guiding washer or member 98, attached as by means of a snap ring 98a to the stem, with such guiding member 98 coacting with the interior surface of the cylindrical seat member 86, for guiding the axial movement of the piston member. An orifice 100 extends through the member 98 for passing fluid therethrough. A passage 102 communicates chamber 72 with chamber 36 in valve body 26 while passage 104 communicates chamber 68 with chamber 34. Moreover, a passageway 106 extending through the skirt of cap member 80 communicates passage 104 with the interior cylinder chamber 82.

A fluid transmission line 108 may connect distributing port 22a of the distributing valve 20 port 28 of valve 10, while distributing line 110 may connect distributing port 22 of the distributing valve 20 with port 28b of valve 10. Flexible fluid transmission line 112 communicates with line 110 and extends to the ports 114, 114a of motor units 16, 160 whileports 116, 116a of the motor units 16, 16a, or in other words, the piston rod ends of the motor units are connected by flexible transmission line 118 back to port 28a of the valve 10. In the illustration shown, two motor units are illustrated, but it will be understood that any desired number of motor units including only one motor unit could be utilized in this system.

Operation of the system illustrated to tip back the bucket member 14 to a position illustrated for instance in FIG. 2 may be as follows:

The spool 20b of the distributing valve 20 is moved axially, as by means of the handle 20a, of the valve, so as to pressurize port 22a of the distributing valve, while connecting port 22 of the valve back to the reservoir 18a in the system. Pressurizing port 22a causes fluid pressure to flow through line 108 to port 28 of regenerative valve 10, wherein the pressurized fluid flows from chamber 34 through openings 52 in valve member 32 to openings 54, then through the latter and out port 28a to fluid transmission line 118. From line 118 to pressurized fluid flows to the piston rod ends of the motor units 16, 16:: via ports 116, 116a, thereby driving the pistons and associated piston rods inwardly with respect to the cylinder portions of the motor units, and causing the bucket to tip or pivot upwardly (as viewed in FIG. 2) about its pivot point 18. Pressurized fluid entering port 28 in valve will also flow from chamber 34 through passage 104 and passage 106 to the cylinder chamber 82, thereby acting on piston 84 to urge it to the position shown in FIG. 1.

The pressurized fluid flowing through orifice plate 56 via tapered orifice opening 58 therein, causes a pressure drop across opening 58 thereby providing a differential pressure between passages 104 and 102 in the valve member 10, which in effect provides a greater pressure in passage 104 as compared to passage 102, and therefore aids spring 84a in keeping the check poppet valve 87 on the seat 86, thus preventing pressurized fluid from escaping through from passage 102 and chamber 72 to port 28b.

Fluid in the piston ends of motor units 16, 16a will of course upon retraction of the piston rods flow via motor ports 114, 11 4a through line 112 to port 22 of distributing valve 20, which, as aforementioned, is connected to reservoir.

Now to dump the bucket member 14 or in other Words to pivot it in a clockwise direction (with respect to FIG. 2) the spool of the distributing valve may be shifted axially in the opposite direction, such that port 22 of the distributing valve is pressurized, and port 22a is connected back to the reservoir.

Pressurizing of port 22 causes pressurized fluid to flow via the line to port 28b of valve 10, and also via the line 112 and motor ports 114, 114a, to the piston ends of the motor units 16, 16a, thereby driving the piston rods outwardly. The resulting increased pressure in the piston rod ends of the cylinders of the motor units is reflected in increased pressure at ports 116, 116a and in the line 118, resulting in increased pressure at port 28a of the valve 10.

Chamber 70 in the valve 10 is pressurized due to the pressurized fluid from distributing valve 20 entering port 28b and since poppet valve member 87 is maintained in sealing engagement with valve seat 86, the pressurized fluid flowing into valve 10 via line 118, flows through tubular member 32, through orifice 58 of orifice plate 56, then to openings 52. From openings 52, the fluid flows into chamber 34, and then out port 28 and via line 108 back to distributing port 22a of the distributing valve 20, and then to reservoir.

However, since there is a pressure dropacross orifice plate member 56 (i.e. a greater pressure in lower section 64a of member 32 as compared to upper section 64) valve member 32 is caused to move axially against spring 42 and in a direction to close off either partially or fully openings 52 in the valve member. It will be seen that surface in the valve 10 coacts with member 32 upon axial movement thereof to close off openings 52. Thus the fluid flow coming from ports 116, 116a of the motor units is regulated by the orifice plate member 56.

Closure of ports 52 results in a considerable pressure differential between the pressure at port 28b and the pressure in cylinder chamber 82 and thus the relatively higher pressure at port 28b causes the piston member 84 to move against spring member 84a, thereby releasing some of the precompression on spring member 88 and movement of shoulder portion 90 on piston 84 away from valve 87. Such movement of the piston member 84 thus permits the relatively high pressure in chamber 72 to move valve member 87 away from its seating or sealing engagement with valve seat 86, and permits the pressure in chamber 72 to flow into chamber 70, since such pressure in chamber 72 is of a generally slightly higher pressure and that at port 2%. The fluid pressure moving from chamber 72 into chamber 70 then flows out port 28b into line 110, and then through line 112 to motor ports 114, 114a thus flowing back into the motor units at the piston ends thereof. Accordingly, the pump in the system has to supply only the rod displacement of the motor unit or units, in a dumping operation, and the regenerative function is accomplished to accelerate the dumping cycle.

Should the load in the bucket 14 try to exceed the oil or fluid input to the motor unit or units during a dumping operation, the pressure at motor ports 114, 114a will fall, thereby reducing the pressure at valve port 28b and tending to permit valve mechanism 66 to close, thereby restricting the exhaust of pressurized fluid from chamber 72 and thus from the piston rod ends of the motor units. Thus, cavitation effects will be prevented in the motor units.

If the control valve 20' is in neutral position (more specifically ports 22, 22a being closed to pressurized fluid) and the loading mechanism is run or forced into a pile of material in a direction such that the impact is effective in a direction to extend the piston rods of the bucket motor units 16, 16a, fluid pressure or oil trying to get out of the cylinder ports 116, 116a might actuate the valve mechanism 30, but the pressure cannot exit through port 28b since valve port 22 in the directional valve is closed, so that oil can not be lost from the piston rod ends of the motor units.

If the bucket is run into a pile of material such that the impact is in a direction causing retraction of the piston rods of the motor units, the oil trying to escape through the ports 114, 114a, of the motor unit might actuate piston 84 against the resistance to compression of its spring member 84a but such pressure can not escape from chamber 70 due to check valve member 87, so that such impact compression load will be carried on the full piston area of the motor unit or units.

It will be seen that the normal metering action provided by the positioning of spool 20b of the directional control valve 20 allows controlled regeneration within the limits of the flow of the system, and a range established by the selection of the size of the orifice in plate member 56.

The terms and expressions which have been used are used as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding any equivalents of any of the features shown, or described, or portions thereof, and it is recognized that various modifications are possible within the scope of the invention claimed.

I claim:

1.. A control valve for use in a power system for providing a regenerative circuit for an associated fluid powered, double acting motor unit comprising, a valve body having first and second chambers therein, a first passageway communicating said chambers with one another, a first valve mechanism disposed in said passageway and extending into said first and second chambers, said first valve mechanism comprising an axially movable sleevelike member, resilient means urging said sleeve-like member in one axial direction, said sleeve-like member having axially spaced aperture means communicating the first chamber and the second chamber respectively with the interior of said sleeve-like member, a port communicating each of said chambers with the exterior of the valve body, an orifice plate disposed interiorly in said sleevelike member inter-mediate said space-d aperture means and adapted to create a pressure drop across said plate upon application of fluid pressure to one of said ports, surface means in said valve body adapted for coaction with certain of the aperture means, to close the same upon predetermined axial movement of said sleeve-like member against the resistance to compression of said resilient means, another valve mechanism disposed in said body and extending into a third chamber, a port com-municating said third chamber with the exterior of the valve body, said other valve mechanism including a piston member axially movable in a cylinder chamber, passage way means communicating said cylinder chamber with said first chamber, resilient means urging said piston member outwardly of said cylinder chamber, said piston member including a stem portion projecting therefrom, a poppet-like valve member slidably mounted on said stern portion, resilient means extending between said poppet-like valve member and said piston member and urging said poppet-like valve member away from said piston member, a valve seat disposed in said valve body, passageway means communicating the valve seat with said second mentioned chamber, said poppet-like valve member being adapted for sealing engagement with said valve seat for closing said third chamber from the fluid pressure in said second chamber, but being disengageable from said valve seat upon movement of said piston member in a direction away from said poppet-like valve member and said predetermined axial movement of said sleevelike member.

2. In a control valve for use in a fluid power system for providing a regenerative circuit for a double acting, fluid powered motor unit comprising, a valve body, having first, second and third chambers therein, a port communicating each of said chambers with the exterior of said body, a first passageway communicating said first and second chambers, a second passageway communicating said third and second chambers, a check valve mechanism normally closing said third chamber from said second passageway, said check valve mechanism including pressure responsive means in said third chamber normally maintaining said check valve mechanism in closed condition but being responsive to predetermined pressure in said third chamber to permit said check-valve mechanism to be opened by fluid pressure in said second passageway and said second chamber, and another valve mechanism disposed in said first passageway for controlling the flow of pressurized fluid into and from said first and second chambers via the associated of said ports, said other valve mechanism comprising an axially movable sleeve extending into said first and second chambers and through said first passageway, said sleeve having axially spaced apertures therethrough, a transverse orifice plate disposed interiorly of said sleeve and intermediate said apertures, said apertures communicating the associated of said first and second chambers with the interior of said sleeve, and means adapted for coaction with the apertures that are associated with said first chamber to close the last mentioned apertures upon predetermined axial movement of said sleeve due to application of fluid pressure to said second chamber whereby said check valve mechanism opens to permit exhaust of fluid pressure from said second chamber vi-a said third chamber and associated port.

3. A control valve in accordance with claim 2, wherein said pressure responsive means comprises a piston one end of which is adapted to be exposed to fluid pressure in said third chamber, resilient means on the other end of said piston urging said piston in a direction to cause closure of said check valve mechanism, and passageway means communicating said other end of said piston to said first chamber.

4. A fluid power system comprising in combination, a reciprocal, double acting, fluid powered motor unit, a source of actuating fluid, a distributing valve coupled to said source, a control valve coupled to said distributing valve and to said motor unit, said control valve comprising a valve body, first and second chambers in said body, a valve mechanism disposed in said first and second chambers and being movable axially therein, said valve mechanism comprising an axially shiftable sleeve member, an orifice plate disposed interiorly of said sleeve member, the latter having spaced groups of apertures therethrough communicating the interior of said sleeve member with respectively said first chamber and said second chamber, means in said valve body for closing off the group of apertures communicating with said first chamber upon predetermined axial movement of said sleeve member, said first chamber being coupled to a distributing port in said distributing valve for fluid transmission therebetween,

and said second chamber being coupled to one end of said motor unit for fluid transmission therebetween, said control valve having a third chamber therein, passageway means in said body coupling said third chamber to said second chamber, fluid transmission means coupling said third chamber to another distributing port of said distributing valve and to the other end of said motor unit, poppet-like valve means in said third chamber normally closing said third chamber from communicating with the last mentioned passageway means and said second chamber, and pressure responsive means in said third chamber operative to maintain said poppet-like valve means in closed position, said pressure responsive means being operative to permit opening of said poppet-like valve means upon predetermined axial shifting movement of said sleeve member to close the interior of said sleeve member from communicating with said first chamber, and upon application of fluid pressure to said third chamber from said distributing valve.

5. In a control valve for use in a pressurized fluid power system comprising, a body, a plurality of biased valve mechanisms mounted in said body, one of said valve mechanisms comprising a sleeve-like member, inlet and outlet ports in said body communicating the exterior of the latter with said one valve mechanism, said member having openings therein communicating the interior of said member with a respective one of said ports, said member being shiftable axially in said body for closing off certain of said openings, means disposed transversely interiorly of said member for creating a pressure drop therethrough to cause said axial shifting of said member, said means comprising a plate having an orifice extending therethrough, means for maintaining said plate in predetermined transverse position in said member, said orifice being defined by converging surface Portions on one side of said plate, and said other valve mechanism comprising a piston member dispose-d for axial movement in a cylinder chamber, said piston member including a stem projecting therefrom, a valve member mounted for relative sliding movement on said stem, a passageway communicating said piston member with said one valve mechanism, a port in said body communicating the exterior of the latter with said passageway, a valve seat in said passageway, and means normally urging said valve member into sealing engagement with said seat, said valve member being adapted to be moved from said seat upon predetermined axial shifting of said sleeve-like member.

6. In a control valve for use in a power system for providing a regenerative circuit for an associated fluid powered double-acting motor unit comprising, a body, a pair of chambers in said body, each of said chambers having a port communicating the respective chamber with the exterior of the body, passageway means communicating said chambers with one another, a valve mechanism disposed in said chambers and extending through said passageway means, said valve mechanism including an axially slidable sleeve-like member, said sleeve-like member having lengthwise spaced apertures therethrough, orifice means disposed in said sleeve-like member intermediate said apertures for creating a pressure drop across said orifice means and thus causing axial movement of said sleeve-like member upon application of fluid pressure to one of said ports, means in said body adapted for coaction with certain of said apertures to close off the latter upon predetermined axial movement of said sleeve-like member, and another valve mechanism disposed in said body, said other valve mechanism comprising a piston member having a stem portion projecting therefrom, said piston member being disposed in a cylinder chamber for axial movement therein, means urging said piston member in a direction out of said cylinder chamber, a poppet-like check valve disposed in slidable relation on said stem portion, a valve seat adapted for sealing engagement with said check valve, passageway means communicating said cylinder chamber with one of the first mentioned chambers and other passageway means communicating said check valve with the other of said first mentioned chambers, said check valve being adapted to close the last mentioned passageway means, and a port communicating said last mentioned passageway means with the exterior of the body.

7. A control valve in accordance with claim 6, wherein said valve seat comprises a tubular-like member extending into said last mentioned passageway, said stern portion extending into said valve seat, and means on said :stem portion coacting with the interior of said valve seat, for guiding the axial movement of said piston member.

8. In a fluid power system for actuating a reciprocal type double-acting motor unit comprising in combination, a distributing valve having a pair of distributing ports, a control valve, said control valve comprising a valve body, a pair of valve mechanisms disposed in said body, said body having first and second ports communicating the exterior thereof with one of said valve mechanisms, said body having a third port communicating the exterior of said body with the other of said valve mechanisms, fluid transmitting means connecting said first port to one of said distributing ports of said distributing valve, fluid transmitting means connecting said second port to one end of said motor unit, and fluid transmitting means conmeeting said third port to the other distributing port of said distributing valve and to the other end of said motor unit, one of said valve mechanisms comprising a poppet-like valve member and the other of said valve mechanisms comprising an axially shiftable sleeve-like member, and orifice means in said sleeve-like member adapted to create a pressure drop thereacross to cause axial shifting movement of said sleeve-like member and opening of said poppet-like valve member upon application of fluid pressure to said second port, said valve mechanisms being operative to close in opposite directions, and said orifice means comprising an orifice plate having a circular orifice therethrough, axially spaced groups of openings through said sleeve-like member communicating the interior of said sleeve-like member with the exterior thereof, said orifice plate member being disposed intermediate said groups of openings, and passageways means in said body communicating said poppet-like valve member with said sleeve-like member.

9. A control valve for use in a power system operating a fluid pressure motor unit comprising, a valve body having first and second chamber means, a port communicating each of said chamber means with the exterior of said body, a third chamber means disposed adjacent said first mentioned chamber means, a first passageway communicating said third chamber means wtih said first chamber means and a second passageway communicating said third chamber means with said second chamber means, a port communicating said third chamber means with the exterior of said body, valve means disposed for axial movement in said third chamber means and adapted for opening and closing said third chamber means from said second passageway, said valve means including pressure responsive means for normally maintaining the same in closed position and being operative for opening said valve means via said second passageway in response to a predetermined pressure in said second chamber means, and other valve means disposed in said first and second chamber means operative for controlling fluid pressure to and from said first and second chamber means via said associated ports, said other valve means including sleeve-like member disposed for axial movement in said first and second chamber means and having at least two sets of axially spaced apertures communicating the respective first and second chamber means with the interior of the sleeve-like member, said sleeve-like member having restricted orifice means extending transversely thereof generally intermediate the respective sets of apertures and being operative to cause a pressure drop thereacross in one direction in response to a predetermined pressure in said first chamber means for maintaining said first mentioned valve means via said first passageway in said normally closed position, and being operative to cause a pressure drop thereacross in the opposite direction in response to a predetermined pressure in said second chamber means, said pressure drop in the opposite direction being operative to axially move said sleeve-like member for closing-off one set of apertures communicating with said first chamber means for opening said first mentioned valve means via said second passageway.

10. A control valve in accordance with claim 9, wherein said first mentioned valve means includes a piston member having a stem portion extending axially from one end thereof, a poppet-like valve member mounted for relative axial movement on said stern portion, a valve seat disposed in said third chamber means, and resilient means normally urging said poppet-like valve member into sealing engagement with said valve seat.

11. A control valve in accordance with claim 10, whercin said valve seat comprises a tubular-like member having oppositely disposed apertures communicating with said second passageway, said stem portion extending axially into said tubular-like member, and guide means on said stem portion coacting with the interior of said tubularlike member for guiding axial movement of said piston member.

12. A control valve in accordance with claim 10, in-

cluding other resilient means coacting with said piston member adjacent the end remote from said stem portion for urging said piston member in a direction to cause closure of said valve means.

13. A control valve in accordance With claim 9, including in combination, a distributing valve, fluid transmission line means coupling said control valve to said distributing valve, said control valve and distributing valve being adapted for coupling to opposite ends of said motor unit, whereby said control valve is operative for returning fluid being exhausted from one end of said motor unit through the control valve and directly to the opposite end of said motor unit upon actuation of the latter in one direction.

14. A control valve in accordance with claim 9 including in combination, a source of actuating fluid, a distributing valve coupled to said source, fluid transmission line means coupling said distributing valve to said control valve via the port in said first chamber means, and coupling said control valve via the port in said second chamber means to one end of said motor unit, and other fluid transmission line means coupling said distributing valve to the control valve via the port in said third chamber means, and coupling said control valve and distributing valve to the opposite end of said motor unit.

References Cited by the Examiner EDGAR W. GEOGHEGAN, Primaly Examiner. SAMUEL LEVINE, BRUCE L. ADAMS, Examiners. P. T. COBRIN, Assistant Examiner. 

1. A CONTROL VALVE FOR USE IN A POWER SYSTEM FOR PROVIDING A REGENERATIVE CIRCUIT FOR AN ASSOCIATED FLUID POWERED, DOUBLE ACTING MOTOR UNIT COMPRISING, A VALVE BODY HAVING FIRST AND SECOND CHAMBERS THEREIN, A FIRST PASSAGEWAY COMMUNICATING SAID CHAMBERS WITH ONE ANOTHER, A FIRST VALVE MECHANISM DISPOSED IN SAID PASSAGEWAY AND EXTENDING INTO SAID FIRST AND SECOND CHAMBERS, SAID FIRST VALVE MECHANISM COMPRISING AN AXIALLY MOVABLE SLEEVELIKE MEMBER, RESILIENT MEANS URGING SAID SLEEVE-LIKE MEMBER IN ONE AXIAL DIRECTION, SAID SLEEVE-LIKE MEMBER HAVING AXIALLY SPACED APERTURE MEANS COMMUNICATING THE FIRST CHAMBER AND THE SECOND CHAMBER RESPECTIVELY WITH THE INTERIOR OF SAID SLEEVE-LIKE MEMBER, A PORT COMMUNICATING EACH OF SAID CHAMBERS WITH THE EXTERIOR OF THE VALVE BODY, AN ORIFICE PLATE DISPOSED INTERIORLY IN SAID SLEEVELIKE MEMBER INTERMEDIATE SAID SPACED APERTURE MEANS AND ADAPTED TO CREATE A PRESSURE DROP ACROSS SAID PLATE UPON APPLICATION OF FLUID PRESSURE TO ONE OF SAID PORTS, SURFACE MEANS IN SAID VALVE BODY ADAPTED FOR COACTION WITH CERTAIN OF THE APERTURE MEANS, TO CLOSE THE SAME UPON PREDETERMINED AXIAL MOVEMENT OF SAID SLEEVE-LIKE MEMBER AGAINST THE RESISTANCE TO COMPRESSION OF SAID RESILIENT MEANS, ANOTHER VALVE MECHANISM DISPOSED IN SAID BODY AND EXTENDING INTO A THIRD CHAMBER, A PORT COMMUNICATING SAID THIRD CHAMBER WITH THE EXTERIOR OF THE VALVE BODY, SAID OTHER VALVE MECHANISM INCLUDING A PISTON MEMBER AXIALLY MOVABLE IN A CYLINDER CHAMBER, PASSAGEWAY MEANS COMMUNICATING SAID CYLINDER CHAMBER WITH SAID FIRST CHAMBER, RESILIENT MEANS URGING SAID PISTON MEMBER OUTWARDLY OF SAID CYLINDER CHAMBER, SAID PISTON MEMBER INCLUDING A STEM PORTION PROJECTING THEREFROM, A POPPET-LIKE VALVE MEMBER SLIDABLY MOUNTED ON SAID STEM PORTION, RESILIENT MEANS EXTENDING BETWEEN SAID POPPET-LIKE VALVE MEMBER AND SAID PISTON MEMBER AND URGING SAID POPPET-LIKE VALVE MEMBER AWAY FROM SAID PISTON MEMBER, A VALVE SEAT DISPOSED IN SAID VALVE BODY, PASSAGEWAY MEANS COMMUNICATING THE VALVE SEAT WITH SAID SECOND MENTIONED CHAMBER, SAID POPPET-LIKE VALVE MEMBER BEING ADAPTED FOR SEALING ENGAGEMENT WITH SAID VALVE SEAT FOR CLOSING SAID THIRD CHAMBER FROM THE FLUID PRESSURE IN SAID SECOND CHAMBER, BUT BEING DISENGAGEABLE FROM SAID VALVE SEAT UPON MOVEMENT OF SAID PISTON MEMBER IN A DIRECTION AWAY FROM SAID POPPET-LIKE VALVE MEMBER AND SAID PREDETERMINED AXIAL MOVEMENT OF SAID SLEEVELIKE MEMBER. 